【爬虫】多线程爬取糗事百科写入文件

'''
爬取糗事百科的段子，将内容和连接爬取下来，写入scv
使用技术：多线程，锁，队列，xpath，csv
'''

import requests
import csv
from queue import Queue
from lxml import etree
import threading


class Creeper(threading.Thread):
    def __init__(self,url_queue,content_queue,*args,**kwargs):
        super().__init__(*args,**kwargs)
        self.url_queue = url_queue
        self.content_queue = content_queue

    def run(self):
        while True:
            if self.url_queue.empty():
                break
            url = self.url_queue.get()
            self.parse_page(url)

    def parse_page(self,url):
        headers = {"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
        response = requests.get(url,headers=headers)
        text = etree.HTML(response.text)
        divEle = text.xpath('//div[contains(@class,"article block")]')
        for div in divEle:
            content = div.xpath('.//a[@class="contentHerf"]//span[1]//text()')
            new_content = "\n".join(list(map(lambda x:x.replace('\n',''),content)))
            a_url = "https://www.qiushibaike.com" + div.xpath('.//a[@class="contentHerf"]/@href')[0]
            self.content_queue.put((new_content,a_url))

class SaveFile(threading.Thread):
    def __init__(self,content_queue,writer,lock,*args,**kwargs):
        super().__init__(*args,**kwargs)
        self.content_queue = content_queue
        self.writer = writer
        self.lock = lock

    def run(self):
        while True:
            try:
                content,link = self.content_queue.get(timeout=30)       # 设置超时时间
                # 写入文件必须加锁
                self.lock.acquire()
                self.writer.writerow((content,link))
                self.lock.release()
                print('保存一条')
            except:
                break


def main():
    url_queue = Queue(100)
    content_queue = Queue(300)
    base_url = "https://www.qiushibaike.com/text/page/{}/"
    gLock = threading.Lock()
    # 解决写入中文乱码
    f = open('糗事百科.csv','a',encoding='utf-8-sig',newline="")
    header = ['content','link']
    writer = csv.writer(f)
    writer.writerow(header)

    for i in range(1,13):
        url = base_url.format(i)
        url_queue.put(url)

    for i in range(2):
        c = Creeper(url_queue, content_queue)
        c.start()

    for i in range(2):
        s = SaveFile(content_queue,writer,gLock)
        s.start()



if __name__ == '__main__':
    main()